OpenRL errors are displayed in console if duplicating multiple objects during autobake, with a small atlas size (progressive lightmapper)

1. Load attached project 'ProgressiveOpenRLError'
2. load scene 'openRL error'
3. Select the 'cubes' gameobject i hierarchy
4. Hit ctrl+D to duplicate the cube layer (command+D on mac)
5. Move the new cubes up a bit
6. Repeat step 4 & 5 repeatetly until the error is displayed or unity crashes

*note: it's possible the crash only occurs if the GICache has not been cleared

tested with:
Unity 2018.1.0a1